Usually you should only send an LOCI after a decision has been made or after three or so months complete with no response.

Thats the conventional wisdom, but this late in the cycle it might not be a bad idea to send an loci to a school if you have something substantive to update or want to throw the hail-mary ("I will withdraw all other apps if accepted"). Ive always thought you might as well try to keep yourself from getting WL with an loci, but make sure you actually have something of importance to tell them. AdComms dont like reading extra stuff if its just BS.

I'm of the opinion that you can (and arguably should) send one if you haven't heard back from the school in a while (in any way, shape, or form). Schools will add the letter to their file, and will take note of your interest. Schools are trying to craft the best incoming class, and if they believe that you will attend if admitted, it helps make their decision that much easier.

fwiw I sent Stanford a LOCI at a random time in Jaunary and did not send Michigan one after being quasi-held. I got into Stanford and was WL'd at Michigan.

BioEBear2010 wrote:I'm of the opinion that you can (and arguably should) send one if you haven't heard back from the school in a while (in any way, shape, or form). Schools will add the letter to their file, and will take note of your interest. Schools are trying to craft the best incoming class, and if they believe that you will attend if admitted, it helps make their decision that much easier.

fwiw I sent Stanford a LOCI at a random time in Jaunary and did not send Michigan one after being quasi-held. I got into Stanford and was WL'd at Michigan.

I second this. It can especially be beneficial for schools that don't often go to the WL (as in, use it as a soft reject); at those schools you really want to make sure you make your pitch as much as possible before you get the WL of death.